SU1659461A2 - Data recording and reproduction technique - Google Patents

Abstract

This invention relates to a magnetic recording technique, in particular to recording and reproducing methods. The purpose of the invention is to increase the reliability of reproduction of recorded digital information. When receiving a clock signal during reproduction, the pulse sequence formed by extreme values of the reproduced signal and zero crossing of the reproduced signal is analyzed by the duration of the appearance of pulses and when the duration of the period between pulses of the pulse sequence is exceeded by more than 3/4 from the period of the clock signal There is a forced preparation for the time division of the total signal into a clock signal. 2 Il.

Description

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This invention relates to a magnetic recording technique, in particular to recording and reproducing methods.

The purpose of the invention is to increase the reliability of reproduction of recorded digital information.

FIG. 1 is a timing diagram explaining the method; in fig. 2 is a diagram of an apparatus for implementing the method.

The device contains a reference signal generator 1 and a digital information source 2, the outputs of which are connected to the input of converter 3, the output of which is connected to serially connected shaper 4, recording amplifier 5, recording head 6, playback head 7, reading amplifier 8, shaper sequence generator 9, the first 10 and second 11 delay elements, the first output of the OR element 12. the first 13 and the second 14 kip-relay and the first

the input of the first element is And 15, the output of which is the output of the device, and the second input is connected to the output of the second element And 16, the first input of the last through the third Kipp relay 17 is connected to the output of the first Kipp relay 13, the second input to the output of the driver 9, with the second input of the element OR 12 and the input Reset of the counter 18, the input of the Account of which is connected to the output of the additional element AND 19, the first input of the latter is connected to the high-frequency generator 20, and the second input - to the output of the counter 18 and to the input Reset the first kipp-relay .

The method is implemented as follows.

The reference signal (Fig. 1, a) from the generator 1 of the reference signal and the digital information (Fig. 1.6) from the source 2 of the digital information are fed to the converter 3, where the rectangular two-frequency manio word

about

It is pooled (Fig. 1, c) in accordance with the information signal. Shaper 4, on one-sided fronts of the carrier, forms a new signal (Fig. 1, d), which is amplified by the recording amplifier 5 and is recorded by the head 6 on a magnetic carrier (not shown). The signal from the carrier is reproduced by the head 7 and is amplified in the amplifier 8 (Fig. 1, e). Block 9 forms the main pulse sequence (Fig. 1, e), corresponding to the transitions of the reproduced signal through zero, maximum and minimum (extreme points). To restore a clock signal (with a period Tm), the pulse sequence is twice delayed by a time equal to half the duration of the clock period (Fig. 1, g, h) in elements 10 and 11, respectively, and then all three pulse sequences are combined into one (Fig. 1, nj element OR 12. The first Kip-relay 13 generates clock pulses, with a time division of the combined sequence (with a duration of time the Kip-relay TKr: 3/4 (see figure 1, k), which start the second 14 and third 17 kipp-relays forming gating impulse (Fig. 1, l, n) at intervals from the beginning of the clock period to 5/8 period m from 3/8 clock period to the end of the period, respectively. The second element AND 16 is designed to eliminate part of the false pulses of block 9 (the signal at the output of the element 16 is shown in Fig. 1, m.) The first element AND 17 eliminates the remaining spurious pulses and restores the input information signal (Fig. 1, s). The counter 18c with a volume of N input pulses all the time is filled with clock pulses from the generator 20, whose frequency is selected of condition

N WT,

f ghv -

If the output of the reset of the counter 18 is a signal from the generator 9 with a period less than 3/4, then the counter 18 is reset to the zero (final) state; if, however, a signal with a period greater than or equal to 3/4 Tt must appear, then counter 18, with its output signal indicating overflow, will force a reset or transfer to

the initial state of the first Kipp relay 13. These reset signals are shown in FIG. 1, p. Forced control of the kipp-relay 13 is carried out in the presence of a reproducible pulse sequence

two (or more) zeros of the row. Considering that the input information is random, the probability of two (or more) zeros of the row is 0.25, i.e. every six (three pairs) bits a forced control (reset) of the trip-relay 13 will occur.

Claims (1)

The invention method of magnetic recording and playback of information on the author. St. No. 526002, characterized in that, in order to increase the reliability of reproduction of information, when receiving a clock signal during reproduction before temporal division of a common signal into a clock signal, the pulse the sequence formed by the extreme values and zero-crossing of the reproduced signal is analyzed by the duration of when the duration of the period between mm pulses of the pulse sequence is exceeded by more than 3/4 from the clock signal period, the generated clock signal is reset, followed by the time division of the common signal into the clock signal. 0 I I I I I t ( ffl ./ I, 0 I, f I .0 I .0, Qa I ./. ( L Ji   I I I I I I I I I I I (I I I I I I I I I I I I N I I I I 1 j U . TT -1 - Тт- «4-Тт i - г I- M J ( , / K N- 4 H-- ° H H H-4 I- i. 7J - 4- TV-I-TV-f-TT I i .1У fl FIG. / ) I (I U lj U lf , / FIG 2